Just starting up a new business from scratch with a few mates and money is a little scarce. I am currently saving up for the full version (full-time college student). I was wondering that once I do if my partners could also use it. there is only three of us will need it so I am hoping that is not asking too much.
According to the activation guidelines:
Yes, the same serial number can be used on a PC or a Mac. As per your end-user license agreement you can use Unity on two machines that you own and have exclusive use of. These two machines could be two Macs, two PCs or one PC and one Mac, whatever works best for you.
Also, if you’re tight on the budget, you can just pay $75 to use Unity on a subscription basis. I know some indies go that way if they have a project and they know it’ll only take like a month or so. You can read more on that here.